What is the difference between the getRequestDispatcher(String path) ServletRequest interface and ServletContext interface?

The getRequestDispatcher(String path) method of ServletRequest interface accepts parameter the path to the resource to be included or forwarded to, which can be relative to the request of the calling servlet. If the path begins with a "/" it is interpreted as relative to the current context root.

The getRequestDispatcher(String path) method of ServletContext interface cannot accepts relative paths. All path must sart with a "/" and are interpreted as relative to curent context root. If the resource is not available, or if the server has not implemented a RequestDispatcher object for that type of resource, getRequestDispatcher will return null. Your servlet should be prepared to deal with this condition.

What is the use of ServletContext ?Using ServletContext, We can access data from its environment. Servlet context is common to all Servlets so all Servlets share the information through ServeltContext.

Is there any way to generate PDF'S dynamically in servlets?We need to use iText. A open source library for java. Please refer sourceforge site for sample servlet examples.

What is the difference between using getSession(true) and getSession(false) methods?getSession(true) - This method will check whether already a session is existing for the user. If a session is existing, it will return that session object, Otherwise it will create new session object and return taht object.

getSession(false) - This method will check existence of session. If session exists, then it returns the reference of that session object, if not, this methods will return null.